What do you do once he reaches your husband? What does your husband do?
If you give him any type of release whether you realize it or not because you're just glad he stopped running off with you, you may be rewarding the behavior and he got out of him doing whatever you were asking of him when he pulled his out of your hands.
^ I agree.
Him looking for your husband and screaming for him I think is not ABOUT your husband, per se. It's about him leaving you! He gets some kind of reward for suddenly going to your husband, even if you actually don't let him go. I think what he gets is the cessation of whatever thing you were asking of him before his attention rocketed over onto the arriving other human being.
We often reward horses in ways that we are totally unaware of. The simple 'pause' in our working with a horse that happens when we stop the ground work long enough to recognize and greet a person coming up to the fence is, to the horse, a reward. Work stopped. and, it stopped when another outside person arrived. The smart horse made a mental link between those two that he will not forget.
And, in the case of a horse that is anxious, and is looking for something, 'out there' to make him feel better, he is so predisposed for something to come that it takes almost nothing for him to leave you and go to that thing, and your pause in your work with him, even if you could not help but pause, was his reward.
If you have a round pen, or a smaller arena, start work with him and when your husband comes up, ignore the husband, and try to not pause even one bit. In fact, if the horse starts to call and put a lot of focus on the husband, I'd start making enough commotion that it makes your horse let go of that thought and turn back to see what all the fuss is about. when he does, immediately stop your noise/commotion so that he knows that all he has to do to make this annoying noise cease is to look at you.
You do this over and over, being very careful to turn it on when he leaves you, off when he looks at you. Eventually, he will realize that being with you is better than not . Then, I'd go up and pet him, and put him away.
for 'commotion' you can use a flag that you flap around, or slapping your thigh noisily, or smacking the dirt with a lunge whip, kicking sand (not AT him! just sideways) . Anything that will startle and annoy him. Just make sure you are not directly threatening him. So, don't flap the falg AT him, as if you are driving him. flap it off to the side, to draw his attention.